Chair back

ABSTRACT

A chair back, belonging to the field of office furniture, comprises a stretching mechanism, and a supporting mechanism including a supporting frame, an adjusting lever and a rotor disposed on the supporting frame, a spring disposed on the adjusting lever, and a rope wound across the rotor and having an end connected to the spring and an end connected to the stretching mechanism. A sliding slot is formed in the supporting frame. An adjusting block sliding along the sliding slot is disposed in the sliding slot and connected to the adjusting lever in a threaded manner, and has a side abutting against one end of the spring. The stretching mechanism can elastically change to some extent in the stretching direction thereof, so that when moving in this direction, the back of a user will always cling to the backrest, and thus, the user feels more comfortably

BACKGROUND OF THE INVENTION 1. Technical Field

This disclosure belongs to the field of office furniture, and particularly relates to a chair back.

2. Description of Related Art

Existing chair backs are typically installed on chair back supports through fasteners. After being fixed, the chair backs cannot be moved anymore, and users have to lean against the chair backs at a constant posture and may feel less comfortable when sitting on chairs. Common chair backs cannot elastically stretch or retreat, thus cannot automatically adapt to users, and cannot fulfill a support effect in many cases. Different users, particularly computer users, may change their postures in the process of using computers. For example, when typing with computers, some users are used to sitting straight, some are used to leaning back slightly, some are used to leaning forward slightly, and even some computer users switch their postures between these three ones. Thus, existing chairs are not suitable for different computer users.

BRIEF SUMMARY OF THE INVENTION

The objective of this disclosure is to provide a chair back.

The objective of this disclosure is fulfilled through the following technical solution:

A chair back comprises a stretching mechanism and a supporting mechanism, wherein the supporting mechanism comprises a supporting frame, an adjusting lever and a rotor disposed on the supporting frame, a spring disposed on the adjusting lever, and a rope wound across the rotor and having an end connected to the spring and an end connected to the stretching mechanism; a sliding slot is formed in the supporting frame, and an adjusting block sliding along the sliding slot is disposed in the sliding slot and connected to the adjusting lever in a threaded manner, and has a side abutting against one end of the spring.

Furthermore, the stretching mechanism comprises a stretchable shroud disposed on the supporting frame and at least one load-supporting block disposed on an inner wall of the stretchable shroud;

The load-supporting block is connected to one end of the rope.

Furthermore, a guide block is disposed on an outer side of the outermost load-supporting block and slides along a guide groove.

Furthermore, the guide groove comprises a side limiting part, and top limiting parts are disposed at an upper end and a lower end of the side limiting part.

Furthermore, the chair back further comprises a limiting mechanism;

The limiting mechanism comprises:

At least one guide roller which is located on one side of the load-supporting block and rotates in a direction tangent to a stretching direction of the stretching mechanism; and

At least one guide face which is located on the other side of the load-supporting block and is parallel to the stretching direction of the stretching mechanism.

Furthermore, under the condition of at least two load-supporting blocks, the guide rollers or guide faces on inner sides of the adjacent load-supporting blocks are connected by means of an inner connecting frame.

Furthermore, the chair back further comprises a lock handle provided with a clamping column;

A plurality of clamping grooves are formed in the load-supporting block;

The clamping column is to be embedded in one of the clamping grooves.

Furthermore, the lock handle comprises a pull rod, and the clamping column is hinged to a lower end of the pull rod.

Furthermore, a flexible part for elastically pressing the clamping column is disposed over the clamping column;

The flexible part is a press spring, the pull rod penetrates through an extension port, and the press spring is disposed around the pull rod below the extension port.

Furthermore, when the clamping column is embedded in one of the clamping grooves, a free end of the clamping column is higher than a hinged end of the clamping column and the pull rod.

This disclosure has the following beneficial effects:

According to this disclosure, the stretching mechanism can elastically change to some extent in the stretching direction thereof, so that when moving in this direction, the back of a user can always cling to the backrest, and thus, the user feel more comfortable.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To more clearly explain the embodiments of this disclosure or the technical solution of the prior art, drawings required for the description of the embodiments of this disclosure or the prior art are briefly introduced below. Obviously, those ordinarily skilled in the art can obtain other drawings according to the following ones without creative labor.

FIG. 1 is an overall structural view of an embodiment of this disclosure;

FIG. 2 is a partial structural view of an embodiment of this disclosure;

FIG. 3 is a top view of FIG. 2 of the embodiment of this disclosure;

FIG. 4 is a structural view of a guide block in an embodiment of this disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The technical solutions of the embodiments of this disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments. Clearly, the embodiments described hereafter are merely illustrative ones, and are not all possible ones of this disclosure. All other embodiments obtained by those ordinarily skilled in the art on the basis of the following ones without creative labor should also fall within the protection scope of this disclosure.

As shown in FIG. 1 to FIG. 3, in an embodiment, a chair back comprises a supporting mechanism 20 and a stretching mechanism 30 disposed on the supporting mechanism 20, wherein the stretching mechanism 30 is able to stretch and retract on the supporting mechanism 20 to drive a backrest to move in a stretching direction thereof.

When the chair back is used, the backrest is disposed on the stretching mechanism 30 and assembled on a corresponding part of a chair through the supporting mechanism 20; the backrest stretches out in the initial state, and when a user sitting on the chair presses against the backrest, the stretching mechanism 30 will be horizontally compressed on the supporting mechanism 20 until the user feels comfortable; when the chair back is not used anymore, the stretching mechanism 30 restores to the initial state under the effect of a force output system. In addition, when the user sits on the chair, the stretching mechanism 30 can elastically change to some extent in the stretching direction thereof, so that when moving in this direction, the back of the user will always cling to the backrest, and thus, the user can feel more comfortable.

In one scenario, the supporting mechanism 20 comprises a supporting frame 21, an adjusting lever 22 and a rotor 23 disposed on the supporting frame 21, a spring 24 disposed on the adjusting lever 22, and a rope 25 wound across the rotor 23, wherein one end of the rope 25 is connected to the spring 24, and the other end of the rope 25 is connected to the stretching mechanism 30.

In one scenario, the adjusting lever 22 is connected to the rotor 23 and is a threaded rod, the supporting frame 21 is formed with a threaded hole, and the adjusting lever 22 is disposed on the supporting frame 21 through the threaded hole; and in use, the initial strength of the spring 24 can be adjusted through the adjusting lever 22. In another scenario, multiple limiting slot may be formed outside the adjusting lever 22 and can fulfill clamping and positioning in combination with movable clamping bolts disposed on a mounting base to adjust the initial strength of the spring 24. In one scenario, as shown, a sliding slot 211 is formed in the supporting frame 21, an adjusting block 212 sliding along the sliding slot 211 is disposed in the sliding slot 211 and connected to the adjusting lever 22 in a threaded manner, one side of the adjusting block 212 abuts against one end of the spring 24, and the adjusting lever 22 can be rotated to enable the adjusting block 212 to slide along the sliding slot 211 to adjust the initial strength of the spring 24.

When the chair back is used, the adjusting lever 22, the rotor 23, the spring 24 and the rope 25 of the supporting mechanism 20 form the force output system for outputting a relatively constant supporting force, and the backrest stretches out in the initial state. When the user sitting on the chair presses against the backrest, the stretching mechanism 30 will be horizontally compressed on the supporting mechanism 20 until the user feels comfortable. When the chair back is not used, the stretching mechanism 30 can restore to the initial state under the effect of the force output system. Because an adjustment part of the rotor 23 and the length of a force arm of the rope 25 can vary accordingly with the extension of the spring 24, the user can always obtain a relatively constant supporting force at different positions, and thus feels comfortable. The chair back is high in comfort, can elastically stretch and retract, is not prone to damage, and is beneficial to the health of users sitting in chairs for work or study for a long time.

As shown in FIG. 1 to FIG. 4, in an embodiment, the chair back comprises a supporting mechanism 20, a stretching mechanism 30 disposed on the supporting mechanism 20, and a backrest disposed on the stretching mechanism 30, wherein the stretching mechanism 30 is able to stretch and retract on the supporting mechanism 20;

The stretching mechanism 30 comprises a stretchable shroud 31 disposed on the supporting frame 21 and at least one load-supporting block 32 disposed on an inner wall of the stretchable shroud 31. To facilitate illustration, two load-supporting blocks 32 are shown and are separately located on two inner sides of the stretchable shroud 31;

The load-supporting block 32 is connected to a rope 25;

The backrest is disposed on the stretchable shroud 31.

The rope 25 provides a force for the stretchable shroud 31 through the load-supporting block 32 under the effect of a spring 24.

A guide block 321 is disposed on an outer side of the outermost load-supporting block 32 and slides along a guide groove 50, so that the load-supporting block 32 can steadily move in the stretching direction of the stretching mechanism 30.

In one scenario, the guide groove 50 comprises a side limiting part 51, wherein top limiting parts 52 are disposed at an upper end and a lower end of the side limiting part 51, and the side limiting part 51 is disposed on the supporting frame 21. Under the limiting effect of the side limiting part 51, the backrest will not shake in a lengthwise direction (namely, the left-right direction of the backrest when the backrest is seen from the front); under the limiting effect of the top limiting parts 52, the backrest will not shake in the lengthwise direction and will not shake in a height (lifting) direction either, so that the stability of the backrest disposed on the chair back is improved.

A limiting mechanism 4 is disposed on the supporting frame 21 and is used to guide the movement of the load-supporting block 32, so that the load-supporting block 32 can steadily move in the stretching direction of the stretching mechanism 30.

In one scenario, the limiting mechanism 4 comprises at least one guide roller 41, which is disposed on one side of the load-supporting block 32 and rotates in a direction tangent to the stretching direction of the stretching mechanism 30. To facilitate illustration, one guide roller 41 is shown;

At least one guide face 42 is disposed on the other side of the load-supporting block 32 and is parallel to the stretching direction of the stretching mechanism 30. To facilitate illustration, one guide face 42 is shown.

In use, the movement of the load-supporting block 32 is limited by means of the guide faces 42 and the guide rollers 41, so that the backrest is further prevented from shaking in the lengthwise direction (namely, the left-right direction of the backrest when the backrest is seen from the front).

In one scenario, as shown, with regard to one load-supporting block 32, the guide rollers 41 are located on an outer side of the load-supporting block 32, and the guide faces 42 are located on an inner side of the load-supporting block 32; and in =another scenario, the guide rollers 41 are located on the outer side of the load-supporting block 32, and the guide faces 42 are located on the inner side of the load-supporting block 32;

Under the condition of at least two load-supporting blocks 32, the guide rollers 41 or guide faces 42 on the inner sides of the adjacent load-supporting blocks 32 are connected by means of an inner connecting frame 43 which is disposed on the supporting frame 21, so that the guide rollers 41 or guide faces 42 on the inner sides of the adjacent load-supporting blocks 32 are mounted on the supporting frame 21;

Under the condition of one load-supporting block 32, the guide rollers 41 or guide faces on the inner side of the load-supporting block 32 are connected by means of an inner connecting frame 43 which is disposed on the supporting frame 21, so that the guide rollers 41 or guide faces 42 on the inner side of the load-supporting block 32 are mounted on the supporting frame 21;

The guide rollers 41 or guide faces 42 on the outer side of the load-supporting block 32 are disposed on an outer connecting frame 44 which is located on the supporting frame 21, so that the guide rollers 41 or guide faces 42 on the outer side of the load-supporting block 32 are mounted on the supporting frame 21.

In case where the guide rollers 41 are connected by means of the outer connecting frame 44 or the inner connecting frame 43, a rotary mounting shaft may be disposed on the outer connecting frame 44 or on the inner connecting frame 43 in one scenario, and the coaxial guide rollers 41 are disposed on the mounting shaft; or, in another scenario, the guide rollers 41 may rotate in a direction tangent to the stretching direction of the stretching mechanism 30 to be rotatably disposed on the outer connecting frame 44 or on the inner connecting frame 43.

As shown in FIG. 1 to FIG. 3, in an embodiment, the chair back differs from the chair back mentioned above in that the chair back further comprises a lock handle 60. Specifically, the chair back comprises a supporting mechanism 20, a stretching mechanism 30 disposed on the supporting mechanism 20, a backrest disposed on the stretching mechanism 30, and the lock handle 60, wherein the stretching mechanism 30 is able to stretch and retract on the supporting mechanism 20;

The stretching mechanism 30 comprises at least one load-supporting block 32 disposed on the supporting frame 21 and a stretchable shroud 31 disposed on the load-supporting block 32. To facilitate illustration, two load-supporting blocks 32 are shown and are separately located on two inner sides of the stretchable shroud 31.

A plurality of clamping grooves 320 are formed in the load-supporting block 32;

The lock handle 60 is disposed on the supporting frame 21 of the supporting mechanism 20 and is provided with a clamping column 601, and the clamping column 601 is as wide as the clamping grooves 320.

When the lock handle 60 is pulled to enable the clamping column 601 to disengage from one clamping groove 320, the stretching mechanism 30 can stretch and retract; when the lock handle 60 is pulled to enable the clamping column 601 to be clamped in one clamping groove 320, the stretching mechanism 30 is fixed and stressed and cannot move; because the clamping column 601 is as wide as the clamping groove 320, the stability of the stretching mechanism 30 in the stretching direction is guaranteed. In one scenario, when the back of the user leans against the backrest, the stretching mechanism 30 can be fixed to adjust the position of the backrest in the stretching direction of the stretching mechanism 30.

In one scenario, the supporting frame 21 has an extension port 210 communicated with the outside;

The lock handle 60 comprises a pull rod 602, wherein the clamping column 601 is hinged to a lower end of the pull rod 601, and the pull rod 602 penetrates through the extension port 210.

In one scenario, the clamping column 601 is clamped in one clamping groove 320 to lock the stretching mechanism 30 by the lock handle 60. In one scenario, the pull rod 602 can be pulled upwards to enable the clamping column 601 to disengage from the clamping groove 320, and then, the stretching mechanism 30 can stretch and retract normally; when the pull rod 602 is released, the clamping column 601 will be embedded into the clamping groove 320 again to lock the stretching mechanism 30 by the lock handle 60. In one scenario, the pull rod 602 may be pulled upwards to enable the clamping column 601 to disengage from the clamping groove 320, and is then rotated, so that the pull rod 602 cannot be embedded in the clamping groove 320 due to the angular deviation with respect to the clamping groove 320, and in this case, the stretching mechanism 30 can also stretch and retract normally.

In one scenario, as shown, the pull rod 602 is hinged to the clamping column 601 in such a manner that a rotary shaft is connected to the lower end of the pull rod 602, and that the clamping column 601 is rotatably disposed on the rotary shaft. Of course, in another scenario, the pull rod 602 may be hinged to the clamping column 601 in other manners.

In one scenario, a flexible part 603 for elastically pressing the clamping column 601 is arranged over the clamping column 601. On the one hand, the clamping column 601 can be pressed by the flexible part 603 to be embedded into one clamping groove 320 to lock the stretching mechanism 30 by the lock handle 60; on the other hand, when the pull rod 602 cannot be embedded in the clamping groove 320 due to the angular deviation with respect to the clamping groove 320, the clamping column 601 can be pressed by the flexible part 603 to keep deviating from the clamping groove 320, so that the stretching mechanism 30 can stretch and retract normally.

In one scenario, the flexible part 603 may be a press spring which is disposed around the pull rod 602 below the extension port 210; an upper end of the press spring is limited by a lower end face of the extension port 210, so that the press spring can press against the clamping column 601; in addition, under the limitation of the pull rod 602, the press spring can be stably kept over the clamping column 601;

In one scenario, the flexible part 603 may be an elastic strip, and the clamping column 601 is pressed by the elastic strip.

In one scenario, when the clamping column 601 is embedded in the clamping groove 320, a free end of the clamping column 601 is higher than a hinged end of the clamping column 601 and the pull rod 602. When the hinged end of the clamping column 601 and the pull rod 602 is pulled, the clamping column 601 will disengage from the clamping groove 320.

In one scenario, as shown, the free end of the clamping column 601 is connected to an upper end of the inner connecting frame 43, so that the free end of the clamping column 601 is higher than the hinged end of the clamping column 601 and the pull rod 602. In another scenario, the free end of the clamping column 601 may be connected to an object which is kept static with respect to the clamping column 601 in the direction of the stretching mechanism, for example, the object is disposed on the supporting frame 21, so that the free end of the clamping column 601 is higher than the hinged end of the clamping column 601 and the pull rod 602.

In this specification, reference terms such as “one embodiment”, “example” and “specific example” are intended to indicate that the specific characteristics, structures, materials or features described in this embodiment or example are included in at least one embodiment or example of this disclosure. In this specification, illustrative presentations of these terms do not refer to identical embodiments or examples. In addition, the specific characteristics, structures, materials or features described can be properly combined in any one or more embodiments or examples.

The basic principle, major characteristics and advantages of this disclosure are represented and described above. Those skilled in the art would appreciate that this disclosure is not limited to the above embodiments, and that the above embodiments and the description in this specification are merely for explaining the principle of this disclosure. Different alterations and improvements of this disclosure can be made without departing from the spirit and scope of this disclosure, and all these alterations and improvements should also fall within the protection scope of this disclosure. 

What is claimed is:
 1. A chair back, comprising a stretching mechanism (30) and a supporting mechanism (20), the supporting mechanism (20) comprising a supporting frame (21), an adjusting lever (22) and a rotor (23) disposed on the supporting frame (21), a spring (24) disposed on the adjusting lever (22), and a rope (25) wound across the rotor (23) and having an end connected to the spring (24) and an end connected to the stretching mechanism (30), wherein: a sliding slot (211) is formed in the supporting frame (21), and an adjusting block (212) sliding along the sliding slot (211) is disposed in the sliding slot (211) and connected to the adjusting lever (22) in a threaded manner, and has a side abutting against one end of the spring (24).
 2. The chair back according to claim 1, wherein the stretching mechanism (30) comprises a stretchable shroud (31) disposed on the supporting frame (21) and at least one load-supporting block (32) disposed on an inner wall of the stretchable shroud (31); the load-supporting block (32) is connected to one end of the rope (25).
 3. The chair back according to claim 2, wherein a guide block (321) is disposed on an outer side of the outermost load-supporting block (32) and slides along a guide groove (50).
 4. The chair back according to claim 3, wherein the guide groove (50) comprises a side limiting part (51), and top limiting parts (52) are disposed at an upper end and a lower end of the side limiting part (51).
 5. The chair back according to claim 3, further comprising a limiting mechanism (4), wherein: the limiting mechanism (4) comprises: at least one guide roller (41) which is located on one side of the load-supporting block (32) and rotates in a direction tangent to a stretching direction of the stretching mechanism (30); and at least one guide face (42) which is located on another side of the load-supporting block (32) and is parallel to the stretching direction of the stretching mechanism (30).
 6. The chair back according to claim 5, wherein under the condition of at least two load-supporting blocks (32), the guide rollers (41) or guide faces (42) on inner sides of the adjacent load-supporting blocks (32) are connected by means of an inner connecting frame (43).
 7. The chair back according to claim 2, further comprising a lock handle (60) provided with a clamping column (601), wherein: a plurality of clamping grooves (320) are formed in the load-supporting block (32); the clamping column (601) is to be embedded in one of the clamping grooves (320).
 8. The chair back according to claim 7, wherein the lock handle (60) comprises a pull rod (602), and the clamping column (601) is hinged to a lower end of the pull rod (602).
 9. The chair back according to claim 8, wherein a flexible part (603) for elastically pressing the clamping column (601) is disposed over the clamping column (601); the flexible part (603) is a press spring, the pull rod (602) penetrates through an extension port (210), and the press spring is disposed around the pull rod (602) below the extension port (210).
 10. The chair back according to claim 7, wherein when the clamping column (601) is clamped in one of the clamping grooves (320), a free end of the clamping column (601) is higher than a hinged end of the clamping column (601) and the pull rod (602). 